The six moral foundations (i.e., Care, Equality, Proportionality, Loyalty, Authority, and Purity) have a natural mapping to language, which can be instantiated by identifying words which are used by speakers to communicate their attitudes with respect to each moral foundation. In the above examples, speakers' attentiveness to the Care foundation is apparent from their usage of the words “harmful,” “compassionate,” and “hurt.”
Moral foundations in language were first studied in this way by [1]}, which provided the Moral Foundations Dictionary (MFD) [2]}. The MFD considers each moral foundation, including the “vice” and “virtue” poles of each foundation, as a collection of related words, the usage of which indicates a concern with the given foundation.
In early work, [1]} used the MFD to measure differences in moral values sentiment between conservative and liberal sermons. More recently, researchers have shown that moral value annotation based on the MFT taxonomy can fruitfully be applied to a range of applications and domains [4]}, [5]}. Additionally, extensions and improvements on the initial MFD have been performed by [6]} (extended MFD) and [7]} (MFD 2.0).
